2014年2月25日星期二（DEMO8-2，光照图调制）

粗略看了下，这个DEMO加上了个光照图，

首先定义了个灯光数量，

#define                       NUM_LAMP                              4

以及光照图数组

BITMAP_IMAGE    lightmaps[NUM_LAMP];

 

初始化时，位置不同了

{

                  bitmap->Create_Bitmap( & textures[itext], ( SCREEN_WIDTH / 2) - 4 *( TEXTSIZE / 2), ( SCREEN_HEIGHT / 2 ) - 2 *( TEXTSIZE / 2), TEXTSIZE, TEXTSIZE, 16 );

        

         bitmap->Create_Bitmap( & temp_text, ( SCREEN_WIDTH / 2) - ( TEXTSIZE / 2), ( SCREEN_HEIGHT / 2) + ( TEXTSIZE / 2), TEXTSIZE, TEXTSIZE, 16 );

 

光照图的初始化

bitmap->Load_Bitmap_File( & bitmap16bit, "lightmaps128_24.BMP");

         for ( int itext = 0; itext < NUM_LAMP; itext++)

         {

                  bitmap->Create_Bitmap( & lightmaps[itext], ( SCREEN_WIDTH / 2) + 2 *( TEXTSIZE / 2), ( SCREEN_HEIGHT / 2 ) - 2 *( TEXTSIZE / 2), TEXTSIZE, TEXTSIZE, 16 );

                  bitmap->Load_Image_Bitmap16( & lightmaps[itext],&bitmap16bit, itext % 4, itext / 4, BITMAP_EXTRACT_MODE_CELL );

 

         }

         bitmap->Unload_Bitmap_File( &bitmap16bit );

把数值改了下

 

         int             curr_texture                = 7;

         float scalef                                   = 0.5;

         int         curr_lightmap              = 1;

这个DEMO是用了下面方式调制

Pixel_dest[x,y]rgb = pixel_source[x,y]rgb * ambient +

//                      pixel_source[x,y]rgb * light_map[x,y]rgb

其实，知道原理了，剩下的都顺理成章了

 

         USHORT *                sbuffer                                         = ( USHORT * )textures[curr_texture].buffer;

         USHORT *                lbuffer                                          = ( USHORT * )lightmaps[curr_lightmap].buffer;

         USHORT *                tbuffer                                         = ( USHORT * )temp_text.buffer;

 

         for ( int iy = 0; iy < temp_text.height; iy ++)

         {

                  for ( int ix = 0; ix < temp_text.width; ix ++)

                  {

                          int             rs, gs, bs;

                          int             rl, gl, bl;

                          int             rf, gf, bf;

 

                          USHORT spixel                                   = sbuffer[iy * temp_text.width + ix];                   

                          _RGB565FROM16BIT( spixel, &rs, &gs, &bs );

                          USHORT lpixel                                   = lbuffer[iy * temp_text.width + ix];                   

                          _RGB565FROM16BIT( lpixel, &rs, &gs, &bs );

 

                          rf                                                           = ( scalef * (float) rs ) + ( ( float) rs * (float )rl/(float)64 );

                          gf                                                          = ( scalef * (float) gs ) + ( ( float) gs * (float )rl/(float)64 );

                          bf                                                          = ( scalef * (float) bs ) + ( ( float) bs * (float )rl/(float)64 );

 

                          if ( rf > 255 )

                          {

                                   rf                                                  = 255;

                          }

                          if ( gf > 255 )

                          {

                                   gf                                                 = 255;

                          }               

                          if ( bf > 255 )

                          {

                                   bf                                                 = 255;

                          }                       

                          tbuffer[iy * temp_text.width + ix]       = _RGB16BIT565( rf, gf, bf );

                  }

 

         }

        

        

         bitmap->Draw_Bitmap16( &temp_text, ddraw->getbackbuffer(), ddraw->getbacklpitch(), 0);

         bitmap->Draw_Bitmap16( &textures[curr_texture], ddraw->getbackbuffer(), ddraw->getbacklpitch(), 0);

         bitmap->Draw_Bitmap16( &lightmaps[curr_lightmap], ddraw->getbackbuffer(), ddraw->getbacklpitch(), 0);

 

结果如下图